Various non-limiting embodiments relate generally to aircraft vehicles, and more particularly, to aircraft control systems.
Aircraft vehicles flight control systems typically include various electromechanical switches to selectively enable or disable one or more flight control components. A conventional flight control circuit is illustrated in FIG. 1. The flight control circuit 100 includes an electromechanical switch that is operable in an enabled operating state or a disabled operating state. The electromechanical switch can be constructed as a solenoid including a solenoid load 102. The operating state can be selectively invoked in response to varying an electrical drive current flowing through the solenoid load 102. A voltage source 104 is continuously switched on and off using a pulse-width modulation (PWM) circuit 106 to generate the current that drives the solenoid switch.
Traditional flight control circuits 100 implement a solenoid discharge circuit 105 that includes a Zener diode 108 and a free-wheeling diode 109, which work together to protect one or more flight control system components such as a low side switch 111 connected to the solenoid load 102, for example, when invoking the disabled state by quickly dissipating the stored drive current. However, the Zener diode 108 also realizes a brief solenoid off-state caused by the switching operation of the PWM circuit 106. Therefore, the Zener diode 108 not only dissipates the drive current when invoking the disabled operating state but also dissipates an amount of current while the solenoid load 102 is enabled.